Amine Functionalized Gadolinium Oxide Nanoparticles-Based Electrochemical Immunosensor for Cholera.

Herein, we report the synthesis and functionalization of gadolinium oxide nanoparticles (Gd ₂ O ₃ NPs) to fabricate a highly efficient immunosensor for the detection of Vibrio cholera toxin (CT). Gd ₂ O ₃ NPs were produced in a straightforward manner utilizing the microwave irradiation technique using a domestic microwave oven. X-ray diffraction, transmission electron microscopy, and spectroscopic techniques were used to characterize the structural and physical aspects of Gd ₂ O ₃ NPs. The Gd ₂ O ₃ NPs were then functionalized with 3-(Aminopropyl) triethoxysilane (APTES) and electrophoretically deposited onto an ITO-coated glass substrate. The anti-CT monoclonal antibodies were covalently attached to the APTES-Gd ₂ O ₃ /ITO electrode via EDC-NHS chemistry, followed by bovine serum albumin (BSA). For CT detection, electrochemical response experiments using BSA/anti-CT/APTES-Gd ₂ O ₃ /ITO immunoelectrodes were carried out (5-700 ng mL ^-1 ). The immunoelectrode demonstrated an outstanding electrochemical reaction against CT, with a sensitivity of 8.37 mA ng ^-1 mL cm ^-2 and a detection limit of 1.48 ng mL ^-1 .